Conversion of gases and other hydrocarbon materials into motor fuel, etc.



R. E. BURK I 1,991,593 CONVERSION OF GASES AND OTHER HYDROCARBON MA TERIALS INTO MOTOR FUEL, ETC

Feb. 19, 1935.

Filed March 20, 1930 Co/v vEzTEz 6A5 FORM PAW MATERIAL.

COOLING 6A6 VA Po: OFF TAKE To co NDEN6EE- INVENTOR. r0567? 6. Bu rk A TTORNEYS.

ture of 375-500" C.

Patented Feb. 19, 1935 UNITED STATES PATENT OFFICE CONVERSION OF GASES AND DTHER HY- -DROCARBON MATERIALS FUEL, ETC.

m'ro Mo'roa Robert E. Burk, Cleveland, Ohio., assignor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio Application March 20, 1930, Serial No. 437,338

In the preparation of motor fuels various S118- gestions have been made along the line of cracking liquid or vaporized heavy hydrocarbons by superheated steam and other vapor at a temperae superheated steam howeve'r is an ineihcient heat transfer medium and such other vapors as have been suggested are imprac ticable from reasons of cost or instability, etc.

Moreover, only a relatively low and limited temperature range has been so contemplated, and

the further problems therebeyond have: not been met. In accordance with the present invention however, operation with a heating vapor becomes feasible, and furthermore, gases and waste materials can be readily converted into motor fuel view showing a formof apparatus contemplated.

Referring more particularly to the drawing, there is shown a container 2, which may be of steel or other suitable materiaLand having its inner surface in the reaction zone covered so as to avoid a ferrous surface. The facing material 3 may be of flreclay, sillimanite, etc. For operation where slight pressures are desired, the entire container may in fact be made of such materials. An inlet duct 4,.preferably in ahead 5 which may be removed for occasions of repair, aifords access for gases or .vaporous materials to be operated upon. From the lower portion a: the container a vapor oiftake Bis arranged, being connected to a suitable condenser system (not shown), the detail of which is immaterial. Connecting with the container, preferably at its highest and lowest portions is a conduit '7 providing a circuit for high temperature heating vapors, and heating means 8, as an electric heating element'or gas or other flame jets, provides. a localized vaporizing zone in such conduit. In order to guard against heat losses externally, the entire assemblage is desirably surrounded by a heat insulative wall 9, which advantageously may take the form of a furnace chamber, with outlet flue 10 and heating furnace 11, the latter allowing of firing at such rate as may be desired to-maintain suitable temperatures in the system, without extra drain on the internal heating means.

[At the lower portion of the container 2 is a cool-- ing zone, and an inlet pipe 12 suitably insulative- 1y covered as by a jacket 13 provides a means for the inlet of a cooling gas,.when desired.

As heating means internally of the container, I apply material in gasiform condition, such agents preferably having a high boiling point. For this I mayemploy such materials as zinc, cadmium, alloys of zinc and cadmium or magnesium or mercury, alloys of cadmium and mercury, alloys of magnesium and zinc, etc., salts of high boiling point, as lead chloride, lead bromide, etc. Where the hydrocarbons treated are gases, theheating agent will desirably'have a boiling point about 700 C. i

The hydrocarbon materialsto be converted, as

.for instance gases or vaporized petroleum fractions of heavier character such as gas oil, or residual tars vaporized by help of steam'or the like,- are fed into the reaction zone through the inlet conduit 4, while the heating vapors from the vaporizer 8 circulate into the container through the conduit '7, intermingling with the hydrocarbon gaseous material entering through the conduit 4. Heating may be readily had by direct transfer from the hot gasiform fluid. Preferably, however, I employ the heat of condensation of the hot vapor, it condensing in contact with the hydrocarbons to, be treated and in the transition from vapor to liquid state giving up a very large amount of thermal units as compared with. the

case of mere temperature dropina gasiform fluid without condensation. Moreover, the heat of condensation is liberated at constant temperature, thus affording a factor of temperature con trol. By employing a high boiling material as heating fluid, it can also be readily separated from the hydrocarbons while still at quite high temperature and be. recirculated. The reaction zone.

is free from ferrous surfaces, my research having shown that the catalytic action' of ferrous sur.--

faces is particularly detrimental for conversion reactions of the character contemplated. In the cooler zone beyond the reaction zone, such precautions are not necessary, and the surface may be of convenientmaterial, as steel. To facilitate cooling beyond the reactionzone, I prefer to introduce a cooling gas or vapor) through pipe 12, for example a hydrogen rich gas as obtained from the outlet of the condenser system. Or,

vaporized gas oil or the like may be introduced" to act as cooling agent, and at the same time be also cracked by contact with the hot fluid. The

heating agent is recirculated back through the heater 8 to the top of the container 2, The temperature may be controlled by the boiling point of the particular heating agent used, or by regulation of the pressure in the system higher or lower than atmospheric. For instance, with zinc boiling normally at 918 C., temperatures on such order may be readily directly applied. Or again, with cadmium, temperatures of 778 C. and slightly higher may be readily directly had. If pressure be imposed, pressures on the order of 100- 300 lbs., or more with the lower boiling heating agents may be employed.

As an example of the invention, hydrocarbon gases, for instance refinery gases as derived from distillation or cracking and stripped of all condensible components,are forwarded into the inlet conduit 4, while zinc vapor is provided from the heater 8 and conduit '1. The pressure is desirably just sumcient to afford a good throughput, and the treated vapors discharge through oiftake 6 to be treated for condensation of the condensible portions. Desirably, a cooling gas, as cold tail gas, is supplied through the pipe 12 to facilitate the cooling and further handling of the material from the reaction zone. With the temperature range such as afforded by zinc vapor as heating agent, the products coming from the reaction zone provide a condensate of mixed character, running high in benzol andwith a considerable component of. toluol, and a heavy tar fraction may befurther worked up to yield naphthalene, anthracene, and a reslnoid material suitablefor electric insulative usage, etc.

Again, gas oil or heavier hydrocarbons, including even such materials as cracking coil tar, may be vaporized to be fed into the converter through supply line 4, while a heating vapor is introduced by conduit '7. For this, it is desirable to employ cadmium; or cadmium-mercury alloy may be employed under pressure. Mercury may be employed, the pressure being raised. With zinc or agent of like boiling point the heating time should be short.

If the initial feed through pipe 4 be gas, as refinery gas or natural gas, and the cooling agent introduced at pipe 12 be vapors of gas oil or heavier hydrocarbons to be also cracked, the gasoline hydrocarbons so produced are available in the motor fuel fraction of the condensate. In some instances vapors of gas oil or heavier hydrocarbons may be fed both at inlet 4 and at 12.

By the employment of heating agents which combine with sulphur, as for instance zinc and the metals mentioned, a sulphur-attractive vapor at the temperature'of reaction is provided, and the products formed are desulphurized at the same time.

By. reason of the avoidance of ferrous contact surfaces, reaction of the type here concerned is accomplished in a highly favorable manner, the

uniform application of heat furthermore possible by reason of the heating vapor making additionally a highly uniform character of yield. Op'ration at higher ranges of temperature is thus made feasible, and such waste by-products as refinery gas, and other low molecular weight gases are readily converted into products suitable for motor fuel as such or by blending with customary stocks.

Other modes of applying the principle of the invention may be employed, change being made as regards the details disclosed, provided the features stated in the following claim, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:- A process of converting hydrocarbons to motor fuel, which comprises subjecting a petroleum refinery gas to the action of vapor of zinc.

ROBERT E. BURK. 

